Kavan died as a result of a single stab wound to the chest suffered in an altercation in an alleyway on Langsett Walk, Upperthorpe, on Tuesday, August 14, at 6.45pm.

He was taken to the Northern General Hospital and clung onto life before his death on Saturday, August 18.

Four teenagers arrested in connection with the incident have all been released under investigation.

Three boys – a 16-year-old and two aged 17 – were arrested on suspicion of conspiracy to rob.

An 18-year-old man was questioned on suspicion of attempted murder.

Detective Chief Inspector Jude Ashmore, who is investigating the incident, said members of the public have come forward with information since a public appeal was launched but officers are still trying to figure out what happened.

She said: "Someone, or several people out there, knows what happened to Kavan and know who is responsible for his death.

"I’d like to ask those people to think about Kavan and his family, who have been robbed of a life with their loved one.